Plugs with built-in phase inverters



May 2, 1967 s. F. E. MEYER PLUGS WITH BUILT-IN PHASEv INVERTERS Filed Jn. 22, 1964 FIG.3

, w@ @MIIU INVENTOR SVEN FREDRIK ERHARD MEYER BY (g/L L3 mc K5 ATTORNEY United States Patent O 3,317,880 PLUGS WITH BUILT-1N PHASE INVERTERS Sven Fredrilr Erhard Meyer, Stockholm, Sweden, assignor to Industriaktiebolaget Elektro-variator, Ostersund, Sweden, a corporation of Sweden Filed Jan. 22, 1964, Ser. No. 339,508 Claims priority, application Sweden, Feb. 13, 1963,

8 Claims. (Cl. 339-31) This invention relates to a plug with a built-in phase inverter, said plug having at least three contact pins arranged side Iby side in insulated relationship. According to the invention the said plug is characterized by the fact that two adjoining contact pins are arranged in a portion which is rotatable with respect to the remaining plug, the phase inversion being realized when the rotatable portion is turned from one into another predetermined position.

These features of the invention and the advantages thereof wil become apparent lfrom the following description in which reference is made to the accompanying drawing illustrating an embodiment, chosen by way of example of the plug according to the invention. In the drawing:

FIG. 1 is a longitudinal sectional View of the plu-g, one half of the housing thereof having been removed;

FIG. 2 is a front view of the plug;

FIG. 3 is a view of the fastening lfor the contact pins of the plug, partly in cross section.

Four contact pins 1 to 4 are arranged side by side in the plug and insulated [from each other. Of these two adjoining contact pins are arranged in a portion 5 which is rotatable with respect to the remaining plug. In the preferred embodiment shown in the drawing the two intermediate contact pins 2, 3 are arranged in the rotatable portion 5, but it would also be possible to arrange the two outermost contact pins 1, 2 and 3, 4,. respectively in said rotatable portion 5.

Phase inversion is realized when the rotatable portion 5 is turned from one into another predetermined position. The portion 5 is to be turned yfrom ya position in which pins 1 to 4 are aligned, into another position in Which pins 1 to 4 are also aligned, the portion 5 being thus turned 180.

In a very simple embodiment the cont-act pins 2 and 3 in the rotatable portion 5 are directly connected via individual electric leads 6 and 7 to the cable 10 associated with the plug. Of course, the contact pins 1 and 4 also are directly connected to the cable 10 preferably via individual electric leads 8 and 9.

A-s will appear from the drawing the portion `5 is nondisplaceably but rotatably mounted in a housing 11 for said contact pins 1 t-o `4. In order that the leads 6 and 7 may not be twisted the rotatability of the portion 5 is restricted to 180, said restriction being brought about by means of 4a pin 12 which is adapted to cooperate with a projecting portion 13. However, it is not always necessary to restrict the rotatability of the portion 5. If the connection of the contact pins 2 and 3 to the cable 10 is effected via pins on the portion 5 and springs in the plug housing 14 there is no reason to restrict the rotatability of the portion 5. Such an -arrangement of pins and springs may be preferable when it is desired to have a short plug 1.

The rotatable portion 5 need not necessarily be rotatable in the housing 11 but rnay be movable therein so that it can be withdrawn from and rotated outside the housing 11, whereupon it is again inserted in the housing 11 in its new angular position. The portion 5 may in this case be for instance rectangular so that it is insertable in a corresponding rectangular recess in the 3,3 17,880 Patented May 2, 1967 housing in two different positions only, spaced an angular distance of tfrom each other. The leads 6 and 7 connecting the contact pins 2 Iand 3 to the cable 10 must be of such a length as to permit withdrawal of the porti-on 5 from Athe housing 11.

The above embodiment of the invention was described for purposes of illustration rather than limitation. All possible variations and modifications of the invention are understood as being included within the scope of the appended claims.

What I claim and desire to secure by Letters Patent is:

1. A plug with a built-in phase inverter comprising at least three contact pins arranged side by side in insulated relationship, v

and rotatable means in said plug with two adjoining ones of said contact pins therein mounted rotatable with respect to the remainder of the plug to reposiition said two .adjoining ones of said contact pins with respect to a third one of said contact pins arranged in the remainder of the plug upon movement of said rotatable means whereby the phase inversion is realized when the rotatable means is turned from one into another predetermined position.

2. A plug with a built-in phase inverter comprising a portion of the plug rotatable with respect to the remainder of the plug,

'at least first, second, and third contact pins arranged side by side in insulated relationship in the plug,

said first and second cont-act pins arranged in adjoining relationship in said rotatable portion of the plug,

said third contact pin arranged in the remainder of the plug,

said first and second contact pins arranged in said rotatable portion of the plug so yas to place said iirst contact pin substantially between said second and third contact pins in one position of rotation .and said second contact pin substantially between said iirst and third contact pins at another predetermined position of rotation whereby the phase inversion is realized when the rotatable portion is t-urned from one into another predetermined position.

3. A plug as claimed in ized by a fourth contact pin arranged in the remainder of the plug on the opposite side of said iirst and second contact pins away from said third contact.

4. A plug as claimed in claim 2 further characterized by cam means on said rotatable portion of the plug and stop means on said remainder of the plug cooperating with said cam means restricting the rotatability of the rotatable portion to 180.

5. A plug with a built-in phase inverter comprising at least three contact pins arranged side by side in insulated relationship,

a portion of the plug rotatable with respect to the remainder of the plug having two adjoining ones of said contact pins :arranged in said rotatable portion,

and a third one of said contact pins arranged in the stationary remainder of the plug,

said at least three contact pins connected by electric leads to the cable associated with the plug whereby the phase inversion is realized when the rotatable portion is turned from one into another predetermined position.

6. A plug as claimed in claim 5 further characterclaim 2 further character- 0 ized by a fourth one of said contact pins arranged in said stationary remainder of the plug on the opposite side of said two adjoining ones of said contact pins arranged in said rotatable portion, yaw-ay from said third one of said contact pins. 7. A plug as claimed .in claim 5 further characterized by cam means on said rotatable portion of the plug, and stop means on said remainder of the plug cooperating with said cam means restricting the rotatability of the rotatable portion to 180. 8. A plug as claimed in claim 5 further characterized by clamping means to clamp said cable to the plug to prevent movement yoaf the `cable in relation to the plug and lallow movement of the electric leads to the cable from said two adjoining ones yof said contact pins arranged in said rotatable portion, in rel-a- 4. tion to each other and the electric leads to said third one of said contact pins.

References Cited by the Examiner 5 UNITED STATES PATENTS 3,139,492 7/ 1964 Cage.

FOREIGN PATENTS 1,110,698 7/1961 Germany. 10 947,062 1/ 1964 Great Britain.

418,679 3/ 1947 Itally.

EDWARD C. ALLEN, Primary Examiner.

15 PATRICK A. CLIFFORD, Examiner. I. H. MCGLYNN, Assistant Examiner. 

1. A PLUG WITH A BUILT-IN PHASE INVERTER COMPRISING AT LEAST THREE CONTACT PINS ARRANGED SIDE BY SIDE IN INSULATED RELATIONSHIP, AND ROTATABLE MEANS IN SAID PLUG WITH TWO ADJOINING ONES OF SAID CONTACT PINS THEREIN MOUNTED ROTATABLE WITH RESPECT TO THE REMAINDER OF THE PLUG TO REPOSIITION SAID TWO ADJOINING ONES OF SAID CONTCT PINS WITH RESPECT TO A THIRD ONE OF SAID CONTACT PINS ARRANGED IN THE REMAINDER OF THE PLUG UPON MOVEMENT OF SAID ROTATABLE MEANS WHEREBY THE PHASE INVERSION IS REALIZED WHEN THE ROTATABLE MEANS IS TURNED FROM ONE INTO ANOTHER PREDETERMINED POSITION. 